With state Sen. Chris McDaniel expected to announce a challenge of incumbent U.S. Sen. Roger Wicker on Wednesday, President Trump tweeted an endorsement of Wicker late Tuesday afternoon.

"(Wicker) has been a great supporter and incredible help in getting our massive Tax Cut Bill done and approved. Also big help on cutting regs. I am with him in his re-election all the way!" Trump said in his tweet.

Trump had previously voiced support for Wicker, but not given a formal— or perhaps in this case semi-formal — endorsement.

.@SenatorWicker of Mississippi has been a great supporter and incredible help in getting our massive Tax Cut Bill done and approved. Also big help on cutting regs. I am with him in his re-election all the way!

McDaniel, a Republican state senator who nearly toppled longtime incumbent Sen. Thad Cochran in 2014, is expected to announce a challenge of Wicker in the Republican primary this year at a Wednesday rally in Ellisville.

Both Wicker and McDaniel support Trump, and are expected to battle for conservative Trump-supporting voters in one of the reddest states in the nation.

Recently, McDaniel was listed among former Trump strategist Steve Bannon’s choices to challenge Majority Leader Mitch McConnell’s establishment leadership. But Bannon’s ignominious departure from the White House as Trump’s chief strategist and his fallout with Trump appeared to put a halt to that movement.